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What is the history of triathlons?

The First Triathlon

Today we think of triathlons as popular competitions, but the sport is actually a relatively new phenomenon in the world of athletics. Its roots can be traced back to 1920s France, when competitors raced, biked and swam around the greater Paris region of Joinville-le-Pont, Melun and Poissy. Although these earliest triathlons took place in Europe, it wasn't until about 50 years later in the United States that the triathlon really took off.

Unlike the intense competitions of today, early triathlons actually began as training sessions for runners, cyclists and swimmers. In 1974 in San Diego, Calif.'s Mission Bay area, a group of runners, swimmers and cyclists who trained together at the San Diego Track Club put together some informal races to build up their endurance for their respective sports. These first triathlons were held on summer evenings and gave participants a break from their grueling training schedules.

Led by Jack Johnstone and Don Shanahan, this group of athletes and friends hosted 46 participants in the first official triathlon, the Mission Bay Triathlon, on Sept. 25, 1974. In addition to Johnstone and Shanahan, John Collins, a U.S. Naval Officer, also played a pivotal role in the development of the sport. He took the triathlon to Hawaii, where he worked to bring together the major swimming, biking and running events in Oahu into one huge triathlon event: the Ironman.

How did the Ironman begin and what makes it one of the most intense competitions in the world?